This invention concerns improvements in or relating to photographic processing apparatus. The invention is particularly although not exclusively directed to apparatus of the so-called "dip and dunk" type, wherein a battery of tanks is provided and film to be processed is sequentially passed into chemical solutions and water contained in said tanks, i.e. developers, fixers, washes etc.
Conventional processing apparatus of this type has been in use in the photographic industry for many years and has become a standard of the industry. It has however suffered from a number of disadvantages, as will be explained hereinbelow, which the invention seeks to obviate and which from the manufacturer's view point render the manufacture and maintenance of present apparatus an expensive excercise.
"Dip and dunk" type processors have comprised a plurality of narrow but deep rigid tanks, lately of metal, spun polyethylene and/or polyvinyl chloride sheets assembled together in a mounting frame to form a battery. The tanks which usually are of the same widths and depths but may be varying in lengths are filled with the necessary reagents or water for processing photographic film, and a time-controlled carrier transports the film to be processed sequentially into the reagents holding it in the reagent for periods of time predetermined in the main by the type of film involved.
The tanks, which may be reinforced, are manufactured to shape and in view of recent increases in price of raw materials in the petro-chemical and steel industry they are now very expensive. Furthermore, they can crank in transit or after some use, which requires their replacement, at concomitant expense. Another disadvantageous aspect of their use is that after having been used for certain reagents, for example bleach, they cannot thereafter be used for other reagents in view of potential detrimental action on the subsequent reagent affecting the quality of processing. Replacement is therefore necessary.
Apart from the cost of a new tank, replacing the tank, for whatever reason, also involves increasingly high labour costs, inasmuch as a substantial degree of dismantling of the apparatus is required including removal of various connections from the tank, removal of pumps for circulating the reagents, removal of heaters where installed and removal of gas burst distributing apparatus, all of which have to be reinstalled in the new tank. Moreover, these costs are incurred whether the tank is replaced by a new one, or whether it is simply removed for cleaning (itself involving similar dismantling and cost).
A further disadvantage involving the use or rigid tanks arises when it is desired to change the apparatus over to a different process or to make changes to an existing process. This may come about when for example a different brand of film is to be processed or the manufacturer of a film alters the processing specification for its film and it will usually involve altering the sequence and/or size of tanks in the apparatus. As mentioned previously the tanks may be of different sizes, say the single size, double size and triple size, which are used for holding different reagents. When the process to which an apparatus is set is to be changed, it is necessary to carry out substantial dismantling and rebuilding of the apparatus to rearrange the tanks if possible, again involving high labour costs.
It will thus be understood that the use of rigid tanks, which have become standard in the art, involves high costs and much inconvenience for both the manufacturer and the user of the apparatus.
A further disadvantageous feature of the conventional processing apparatus is the amount of labour which is necessary to build the machine initially so that it can be tested and then partially dismantled for packing and shipping. The intricasy of the known equipment imparts a labour intensive manufacture and thus the cost of manufacture is high. Furthermore being a sophisticated machine, it cannot be expected that the user will assemble the whole machine himself and it is therefore necessary to ship the machine in a partially assembled state. Apart from attracting higher transport rates by its nature, this also involves very involved, meticulous and protective packing for transport.
Because of its size, on many occasions it is necessary to further strip down the present apparatus in order to gain access to the place of installation.
From all the foregoing it will be seen that the conventional apparatus, although being satisfactory in operation, suffers from a number of costly drawbacks which in view of present price trends in labour and raw materials render the machine unattractive in terms of cost and convenience of maintenance. The present invention has therefore been evolved with the aim of improving the situation and providing a processing apparatus which may be less costly to manufacture, transport and to maintain.